Sharp AR-6020V Service Manual page 128

13. Fusing section
A. 20/23 cpm
(1) Mechanism relation diagram
1
HL_PR
HLout
Signal name
MM Main motor
HL_PR Heater lamp control relay
HLout Heater lamp
TH_MY Thermistor UM
TH_US Thermistor US
TS_UM Thermostat UM
No.
1 Heat roller
2 Upper separation pawl
3 Pressure roller
4 Lower separation pawl
(2) Fusing unit drive
The driving of fuser unit is; the driving force is transported to fuser
roller, thru the Main motor (MM) and connection gears, based on
the controlling signal from MCU.
TH_US
TS_UM
2
3
Name
Drives the most of the driving parts except the duplex section, the toner section and the scanner sections.
Turns ON/OFF the control of the heater relay.
Turns ON/OFF the heater lump.
Regulates Heat Roller Temperature at the end of the Heat Roller.
Regulates Heat Roller Temperature at center of the Heat Roller.
Fusing roller overheat protection. Cuts off power supply to heat lamp when over heat condition is
determined.
Name
Applies heat and pressure to toner on paper to fuse it on paper.
Mechanically separates paper which was not naturally separated from the heat roller (heating).
Presses toner on paper to fuse.
Mechanically separates paper which was not naturally separated from the heat roller (heating).
AR-6020V OPERATIONAL DESCRIPTIONS 11 – 21
MM
TH_MY
2
4
2
Function and operation
Function and operation
(3) Heater lamp drive
The surface temperature of the heat roller detected by the thermis-
tor is sent to the MCU.
When the temperature is lower than the specified level, the heater
lamp ON signal is sent from the MCU to the heater lamp drive cir-
cuit on the HL PWB.
The power triac in the heater lamp drive circuit is turned on, and the
AC power is supplied to the heater lamp, lighting the lamp and
heating the heat roller.
To prepare for an abnormally high temperature of the heat roller,
the thermostat is provided for safety.
When the thermostat is opened, the power supply (AC line) to the
heater lamp is cut off.
2